The present disclosure relates to a turbocharger system having a lubricant control system, and to a method of delivering lubricant to a turbocharger.
Turbochargers are well-known devices for supplying air to the intake of an internal combustion engine at pressures above atmospheric pressure (boost pressures). A conventional turbocharger essentially comprises an exhaust gas driven turbine wheel mounted on a rotatable shaft within a turbine housing. Rotation of the turbine wheel rotates a compressor wheel mounted on the other end of the shaft within a compressor housing. The compressor wheel delivers compressed air to the intake manifold of the engine, thereby increasing engine power. The turbocharger shaft is conventionally supported by journal and thrust bearings, including appropriate lubricating systems, located within a central bearing housing connected between the turbine and compressor wheel housing.
The lubricating systems are supplied with lubrication (e.g. oil) which reduces friction between moving parts and stationary parts of the turbocharger, thereby facilitating smooth rotation of the shaft upon which the turbine wheel and compressor wheel are mounted. Seals are provided between the shaft and the central bearing housing, the seals acting to isolate the lubricant used by the lubricating systems from the turbine housing and the compressor housing. Despite the presence of these seals, some lubricant may leak from the lubricating systems into the compressor housing and into the turbine housing. Leakage of lubricant into the compressor housing is undesirable because the compressor wheel will drive the lubricant to the intake of the internal combustion engine to which it is connected. This will cause the lubricant to pass through the internal combustion engine, leading to undesirable effects such as the emission of increased pollution from the internal combustion engine. It is an object of the present disclosure to obviate or mitigate the above problem, or to provide a turbocharger system which is novel and inventive over the prior art.